Herolee has a theory that it's after Superman saves the world, exhausted and reaching up to the sun.

I like this idea for it. I feel like I can still see the blue of the suit and the regular color of the shield as well. Doesn't look quite fully black. Who knows until the movie is out though? It will be a great scene whatever it is I'm sure. That hand reaching towards the sun, just awesome!

Herolee has a theory that it's after Superman saves the world, exhausted and reaching up to the sun.

Yep. Yep. I mean, didn't we get a shot of Superman, from the 3 minute trailer, of film flying up towards a energy beam while he was surrounded by the ocean? I think the last major obstacle that superman will have is taking care of Black Zero, which probably becomes sentient and conscious at the climax of the film.

Plus, if you look closely in the shot, I believe you can see the redness (albeit it being dark since it's drenched in water) of his cape.